view osmo-patches/osmo-bts-rtp-bfi.patch @ 172:60e2d6379fce

osmo-patches/osmo-bts-rtp-bfi.patch: checking in
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 21 Nov 2022 01:05:58 -0800
parents
children f5c4f9a764be
line wrap: on
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diff --git a/src/common/l1sap.c b/src/common/l1sap.c
index 8bcd417..bfdc37f 100644
--- a/src/common/l1sap.c
+++ b/src/common/l1sap.c
@@ -1244,6 +1244,12 @@ static bool rtppayload_is_octet_aligned(const uint8_t *rtp_pl, uint8_t payload_l
 
 static bool rtppayload_is_valid(struct gsm_lchan *lchan, struct msgb *resp_msg)
 {
+	/* Discard Themyscira BFI packets - because we have our own
+	 * TDMA timing, there is no difference for us between receiving
+	 * an explicit BFI packet vs receiving nothing at all. */
+	if (resp_msg->len == 2 && resp_msg->data[0] == 0xBF)
+		return false;
+
 	/* Avoid sending bw-efficient AMR to lower layers, most bts models
 	 * don't support it. */
 	if (lchan->tch_mode == GSM48_CMODE_SPEECH_AMR &&
@@ -1574,6 +1580,7 @@ static int l1sap_tch_ind(struct gsm_bts_trx *trx, struct osmo_phsap_prim *l1sap,
 	struct gsm_lchan *lchan;
 	uint8_t  chan_nr;
 	uint32_t fn;
+	uint8_t bfi[2];
 
 	chan_nr = tch_ind->chan_nr;
 	fn = tch_ind->fn;
@@ -1619,13 +1626,19 @@ static int l1sap_tch_ind(struct gsm_bts_trx *trx, struct osmo_phsap_prim *l1sap,
 		/* Only clear the marker bit once we have sent a RTP packet with it */
 		lchan->rtp_tx_marker = false;
 	} else {
-		DEBUGPGT(DRTP, &g_time, "Skipping RTP frame with lost payload (chan_nr=0x%02x)\n",
-			 chan_nr);
-		if (lchan->abis_ip.osmux.use)
-			lchan_osmux_skipped_frame(lchan, fn_ms_adj(fn, lchan));
-		else if (lchan->abis_ip.rtp_socket)
-			osmo_rtp_skipped_frame(lchan->abis_ip.rtp_socket, fn_ms_adj(fn, lchan));
-		lchan->rtp_tx_marker = true;
+		/* Themyscira change: send explicit BFI packets instead of
+		 * gaps in the RTP stream. */
+		bfi[0] = 0xBF;
+		bfi[1] = 0;	/* TAF will go here */
+		if (lchan->abis_ip.osmux.use) {
+			lchan_osmux_send_frame(lchan, bfi, 2,
+					       fn_ms_adj(fn, lchan), lchan->rtp_tx_marker);
+		} else if (lchan->abis_ip.rtp_socket) {
+			osmo_rtp_send_frame_ext(lchan->abis_ip.rtp_socket,
+				bfi, 2, fn_ms_adj(fn, lchan), lchan->rtp_tx_marker);
+		}
+		/* clear the marker like in the regular code path */
+		lchan->rtp_tx_marker = false;
 	}
 
 	lchan->tch.last_fn = fn;